How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Roy Your Own Question
Roy
Roy, import/domestic specialest
Category: Chevy
Satisfied Customers: 4643
Experience:  ASE master tech for 40 years
3506196
Type Your Chevy Question Here...
Roy is online now
A new question is answered every 9 seconds

Replaced engine in a 1996 blazer 4.3 and now it has 75psi

Customer Question

Replaced engine in a 1996 blazer 4.3 and now it has 75psi oil pressure at all times any idle ?
Submitted: 10 months ago.
Category: Chevy
Customer: replied 10 months ago.
The oil pressure stays at 75psi at idle and when you rev it up it goes to 80-90 I'm not sure what's going
Expert:  Roy replied 10 months ago.

good evening my name is ***** ***** I will assist

it sounds like the sender unit may not be working. I would start by replacing the sender unit. while the sender is out, you can check the actual pressure with a gauge. you can rent a tester at a parts store.

Roy

Customer: replied 10 months ago.
It has a new sender unit in it and I have checked the oil pressure with a machanical gage and is was reading 75 at idle as well
Expert:  Roy replied 10 months ago.

ok, if that is the case then the check valve in the oil pump is the failure. the oil pump will have to be replaced.

Roy

Customer: replied 10 months ago.
Just to make sure the sender unit is the sensor located on the back of the block right
Expert:  Roy replied 10 months ago.

thats correct. if you were wrong you would not have been checking the oil pressure

Roy

please dont forget to rate me as it is the only way I get paid for my efforts

Roy

Customer: replied 10 months ago.
Ok that's what I thought but I checked the oil pressure from the plug on the bottom of the oil filter housing since the oil filter is located up by the radiator and is the only thing that can cause the high oil pressure is the bad oil pump?
Expert:  Roy replied 10 months ago.

the check valve in the pump, yes but you need to replace the entire pump for this.

Roy

Customer: replied 10 months ago.
Can you change the oil pump without removing the engine
Expert:  Roy replied 10 months ago.

yes, more difficult if it is a***** the motor will have to be raised.

Roy

Customer: replied 10 months ago.
Ok and I don't think mentioned it was a new motor I installed not a used or junk yard
Expert:  Roy replied 10 months ago.

ok, makes no difference

it should be warranty from the manufacturer

Roy

Expert:  Roy replied 10 months ago.

how are you makingout

Customer: replied 10 months ago.
It's good now it was the check valve in the oil filter housing I replaced the oil filter housing and oil cooler lines and the pressure is running about 50-55 at idle now
Expert:  Roy replied 10 months ago.

this is where I found the pressure regulator valve. where was this valve you replaced

Roy

Customer: replied 10 months ago.
On the housing the oil filter screws onto
Expert:  Roy replied 10 months ago.

thats interesting.it is not a pressure regulator, just a check valve to retain oil in the filter.

Roy

Customer: replied 10 months ago.
Ya that's what I thought by that's all I done and now it's fine